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73ET/74ET/75ET USERS MANUAL EM-7353-0003B Rev.5
PARAMETER FILE
The parameter file contains information about the 7xET’s system and pen configurations. The 7xET reads this file at
the startup to apply the parameters.
8.2
DATA STORAGE TIME
Data storage time for one CF Card depends upon the following:
1. Storing rate
2. Data storing form
3. Number of channels
There are also CF Cards of different capacities.
Data storage time of a CF Card is calculated as follows:
Record Size
[Date Information] (bytes) + [One Sample Data] (bytes) x [No. of Channels] (points) = [Record Size] (bytes)
Number of Records
[CF Card Memory Size]
*
(bytes) / [Record Size] (bytes) = [Number of Records]
Data Storable Time
[Number of Records] x [Storing Rate] (seconds) = [Data Storage Time] (seconds)
Date information takes 8 bytes and one bit of sampled data takes 4 bytes with the floating point form, 2 bytes with
short integer form. No. of channels must include all channels set to ‘Enable.’
*
[CF Card Memory Size] means the volume of data file (7xET.7xDA) created in the CF Card.
[Example]
Storing rate: 5 sec.
Data storing form: Short integer
Number of channels: 64
CF Card memory size: 118 MB (for 128 MB CF Card)
A record size is calculated as:
8 (bytes) + 2 (bytes) x 64 (points) = 136 (bytes)
The number of records which can be stored in this CF card is calculated as:
123731968 (bytes) / 136 (bytes) = approx. 909794 (records)
Time duration usable for the number of records is:
909794 x 5 (sec.) = 4548970 (sec.) = approx. 1263 Hours. = approx. 52 days
This calculated result is only for approximate estimation since the data file must be smaller than the full capacity of
a CF Card.
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